Mössbauer study on microwave synthesized (Cu,Fe) sulfide composites and correlation with natural mineral—cubanite
In nature, the mineral ‘Cubanite’ with composition CuFe2S3 occurs in orthorhombic structure in the matrix of chalcopyrite and pyrrhotite. Synthesis of this mineral in the laboratory conditions has not been reported yet. An attempt to synthesize the orthorhombic Cu–Fe–Sulfide (cubanite) by resistive as well as microwave heating technique is reported. MW-heated sample shows the presence of orthorhombic component along with isocubanite and pyrrhotite. The synthesized samples were studied in details through XRD and Mössbauer spectroscopy. The synthesis process, responsible for different proportions of the minerals, may indicate the conditions of their genesis in nature. Formation of isocubanite (cubic cubanite) seems unavoidable under the conditions of synthesis. The striking indistinguishable character of cubanite and chalcopyrite could be challenged through Mössbauer hyperfine parameter—the hyperfine field of chalcopyrite (~37 T) being quite different from that of cubanite (~33 T).
KeywordsOrthorhombic cubanite Isocubanite Mössbauer spectroscopy Cu–Fe–S Chalcopyrite–pyrrhotite
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